Strength prediction of T-peel joints by a hybrid spot-welding/adhesive bonding technique

The need of joining methods that best meet the design requirements has led to the increased use of adhesive joints at the expense of welding, fastening and riveting. Hybrid weld-bonded joints are obtained by combining adhesive bonding with a welded joint, providing superior strength and stiffness, and higher resistance to peeling and fatigue. In the present work, an experimental and numerical study of welded, adhesive and hybrid (weld-bonded) T-peel joints under peeling loads is presented. The brittle Araldite® AV138, the moderately ductile Araldite® 2015 and the ductile Sikaforce® 7752 were the considered adhesives. An analysis of the experimental values and a comparison of these values with Finite Element Method (FEM) results in Abaqus® were carried out, which included a stress analysis in the adhesive and strength prediction by Cohesive Zone Models (CZM) considering failure simulation of both the adhesive layer and weld-nugget. It was found that the Sikaforce® 7752 performs best in the bonded and hybrid configurations. The good agreement between the experimental and numerical results enabled the validation of CZM to predict the strength of adhesive and hybrid T-peel joints, giving a basis for reducing the design time and enabling the optimization of these joints.